The interesting thing about dropships from a design perspective is that they are ruinously expensive. For example, a single ERLL placed in a dropship costs 5.6M, and because dropships lose initiative against aero, you need several of these superexpensive weapons just to guarantee the ability to attack. For this reason, it seems like a waste of resources to use a dropship in an assault or pocket warship role rather than several pocket assaultships
http://bg.battletech.com/forums/index.php/topic,11749.msg286916.html#msg286916 or a swarm of fighters which are 1/10th the price. (That's not to say they won't be built---it's easy to imagine cost-plus contractors preferring the more expensive solution, and project managers being sold on the "great big machine", rather than the effective counter.)
As best I can tell, a dropship can do a few things better than anything else:
- High speed interstellar transport. Using a command circuit, travel times on the order of 30 light years/hour are feasible. A jumpship or warship must recharge, and hence can only travel at most 60 light years/week.
- High speed system transport. Smallcraft are of comparable speed but tiny capacity, while warships generally must move slower due to the need for a jump drive.
- Battlefield sniper. A dropship can execute an aerial bombardment with sub-capital weapons. Orbital bombardment is generally frowned upon, because the typical large hit penalty means that many shots doing damage over a wide area are required. An aerial bombardment however is different. For example, a dropship in the last atmospheric hex before the ground row has a to-hit number of 0: 4 gunnery -4 for immobile target, Short range due to an effective 6 hexes from the ground row. Furthermore, the damage doesn't strike a wide area---it just hits the target hex and does half damage to adjacent hexes. This is high quality damage too, because it uses the Shots from Above table. Consequently, only 90 points of damage is required for an expected kill on any canon mech. As far as I can tell from the airborne to surface rules, attacks are allowed on a low-altitude map as well, implying that orbit-to-surface fire can occur every 10 seconds rather than every minute. Surface units generally can't fight back so long as they lack (sub)capital weapons and the dropship stays at altitude 9 or 10 (LOS only goes to altitude 8 = 2km). Surface units also generally can't escape, because dropship movement is measured in mapsheets.
Putting these ideas together we get the Executioner, below.
Executioner
12400 ton Mixed technology spheroid dropship
Thrust 6
Overthrust 9
Structure 18
Nose 407
Sides 401
Aft 411
Control 93
Engine 4539
Fuel 500
Fuel Tanks 10
Structure 446.5
Quarters 360 [Steerage quarters for 72 = 7(base)+13(gunners)+52(bay personnel)]
Crew Battle Armor 86 [43 battlesuits]
Heat Sinks (double) 0 [175 total]
armor (FA) 64.5
24 AMS 12 [2 bays of 2 in each arc]
Ammo (69 shots) 69
2 SCL/1 300 [1 bay aft]
3 SCL/3 750 [1 bay aft]
42 MPL 84 [1 bay of 8 in all arcs but aft, 1 bay of 2 aft]
Screen Launcher 40 [Aft]
Ammo (10 shots) 100
3 Smallcraft 600
17 Aero bays 2550
6 Mech bays 900
Cargo 896
There are 4 transport bays, each with 2 doors.
Bay 1 transports 6 mechs + 240 tons of cargo.
Bay 2 transports 1 smallcraft + 6 aero + 225 tons of cargo.
Bay 3 transports 1 smallcraft + 6 aero + 225 tons of cargo.
Bay 4 transports 1 smallcraft + 5 aero + 206 tons of cargo.
BV: 16036
Cost: 471.4M
Cost Loaded: about double. That's not a coincidence---the goal is after all transport.
The most critical optimization here is speed. Moving 6/9 can pace or outrun heavy aero and all warships, implying that it can outrun the most dangerous opponents as needed. The screen system also aids in escape situations.
The craft has heavy armor, helping it survive any unfortunate attacks. The AMS bays are sufficient to deeply degrade most canon missile carriers, and even some capital missiles. Advanced point defense allows the AMS in one arc to eliminate 828 points of missile damage in one minute.
Placing the larger weapons in the rear is also particularly effective in stern chase situations as an opponent must be substantially faster to engage in sustained non-aft attacks. The smaller MPL bays provide a degree of all-around protection which seems prudent given the overall value of the dropship. The primary value of the subcapital weapons is in the role as execution, as discussed above. Here, the aft weapons fire straight down on targeted enemy forces, reliably eliminating 1/round with 110 damage from above. A 6/9 movement allows it to sideslip 2/3 mapsheets which is plenty mobile compared to ground forces. Note that all weapons can be fired without overheat.
Boarding is unlikely given the speed, but the 43 suits of crew battlearmor
http://bg.battletech.com/forums/index.php/topic,11243.0.html can provide significant defense. The 23 techs can then provide 166.75 marine points, and in a pinch the whole crew+techs could chip in providing 311.75 marine points. The suits are also useful for shifting cargo around, and as an emergency lifeboat.
There are steerage quarters for all, which is cramped but provides much more efficient life support.
My preferred mech would be the Kangaroo
http://bg.battletech.com/forums/index.php/topic,10577.0.html, which is close to ideal for flushing out enemy forces so the Executioner can get to work.
My preferred aerospace might be 12 Alphas, 4 Betas, 1 Gambit scout hunter and 2 Gambit scouts
http://bg.battletech.com/forums/index.php/topic,11316.msg286286.html#msg286286. That's more than there are aero bays, but the Gambit scouts are light enough to move from cargo and launch as needed.
My preferred smallcraft might be 3 Dirks
http://bg.battletech.com/forums/index.php/topic,11749.msg286916.html#msg286916 for dropship hunting operations or 3 Needlers if you are worried about a fast assault ship.
The cargo includes 40 tons of supplies/mech, 20 tons of supplies/aero, 100 days of perishables for all, and 1% of the dropship mass in repair parts, and some leftover tonnage.
